/*
 *  Copyright 2019-2020 Zheng Jie
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package me.zhengjie.config;

import com.fasterxml.classmate.TypeResolver;
import com.google.common.base.Predicates;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.Ordered;
import org.springframework.core.env.Environment;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.domain.Pageable;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.handler.SimpleUrlHandlerMapping;
import org.springframework.web.servlet.resource.PathResourceResolver;
import org.springframework.web.servlet.resource.ResourceHttpRequestHandler;
import org.springframework.web.util.UrlPathHelper;
import springfox.documentation.annotations.ApiIgnore;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.schema.AlternateTypeRule;
import springfox.documentation.schema.AlternateTypeRuleConvention;
import springfox.documentation.service.*;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spi.service.contexts.SecurityContext;
import springfox.documentation.spring.web.DocumentationCache;
import springfox.documentation.spring.web.json.Json;
import springfox.documentation.spring.web.json.JsonSerializer;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger.web.ApiResourceController;
import springfox.documentation.swagger.web.SecurityConfiguration;
import springfox.documentation.swagger.web.SwaggerResource;
import springfox.documentation.swagger.web.UiConfiguration;
import springfox.documentation.swagger2.annotations.EnableSwagger2;
import springfox.documentation.swagger2.mappers.ServiceModelToSwagger2Mapper;
import springfox.documentation.swagger2.web.Swagger2Controller;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import java.util.*;

import static com.google.common.collect.Lists.newArrayList;
import static springfox.documentation.schema.AlternateTypeRules.newRule;

/**
 * api页面 /doc.html
 * @author Zheng Jie
 * @date 2018-11-23
 */
@Configuration
@EnableSwagger2
public class SwaggerConfig {

    private static final String DEFAULT_PATH = "/swagger";

    @Value("${jwt.header}")
    private String tokenHeader;

    @Value("${swagger.enabled}")
    private Boolean enabled;

    @Bean
    @SuppressWarnings("all")
    public Docket createRestApi() {
        return new Docket(DocumentationType.SWAGGER_2)
                .enable(enabled)
                .pathMapping("/")
                .apiInfo(apiInfo())
                .select()
                .paths(Predicates.not(PathSelectors.regex("/error.*")))
                .paths(PathSelectors.any())
                .build()
                //添加登陆认证
                .securitySchemes(securitySchemes())
                .securityContexts(securityContexts());
    }

    /**
     * SwaggerUI资源访问
     *
     * @param servletContext
     * @param order
     * @return
     * @throws Exception
     */
    @Bean
    public SimpleUrlHandlerMapping swaggerUrlHandlerMapping(ServletContext servletContext,
                                                            @Value("${swagger.mapping.order:10}") int order) throws Exception {
        SimpleUrlHandlerMapping urlHandlerMapping = new SimpleUrlHandlerMapping();
        Map<String, ResourceHttpRequestHandler> urlMap = new HashMap<>();
        {
            PathResourceResolver pathResourceResolver = new PathResourceResolver();
            pathResourceResolver.setAllowedLocations(new ClassPathResource("META-INF/resources/webjars/"));
            pathResourceResolver.setUrlPathHelper(new UrlPathHelper());

            ResourceHttpRequestHandler resourceHttpRequestHandler = new ResourceHttpRequestHandler();
            resourceHttpRequestHandler.setLocations(Arrays.asList(new ClassPathResource("META-INF/resources/webjars/")));
            resourceHttpRequestHandler.setResourceResolvers(Arrays.asList(pathResourceResolver));
            resourceHttpRequestHandler.setServletContext(servletContext);
            resourceHttpRequestHandler.afterPropertiesSet();
            //设置新的路径
            urlMap.put(DEFAULT_PATH + "/webjars/**", resourceHttpRequestHandler);
        }
        {
            PathResourceResolver pathResourceResolver = new PathResourceResolver();
            pathResourceResolver.setAllowedLocations(new ClassPathResource("META-INF/resources/"));
            pathResourceResolver.setUrlPathHelper(new UrlPathHelper());

            ResourceHttpRequestHandler resourceHttpRequestHandler = new ResourceHttpRequestHandler();
            resourceHttpRequestHandler.setLocations(Arrays.asList(new ClassPathResource("META-INF/resources/")));
            resourceHttpRequestHandler.setResourceResolvers(Arrays.asList(pathResourceResolver));
            resourceHttpRequestHandler.setServletContext(servletContext);
            resourceHttpRequestHandler.afterPropertiesSet();
            //设置新的路径
            urlMap.put(DEFAULT_PATH + "/**", resourceHttpRequestHandler);
        }
        urlHandlerMapping.setUrlMap(urlMap);
        //调整DispatcherServlet关于SimpleUrlHandlerMapping的排序
        urlHandlerMapping.setOrder(order);
        return urlHandlerMapping;
    }

    private ApiInfo apiInfo() {
        return new ApiInfoBuilder()
                .description("一个简单且易上手的 Spring boot 后台管理框架")
                .title("EL-ADMIN 接口文档")
                .version("2.6")
                .build();
    }

    private List<SecurityScheme> securitySchemes() {
        //设置请求头信息
        List<SecurityScheme> securitySchemes = new ArrayList<>();
        ApiKey apiKey = new ApiKey(tokenHeader, tokenHeader, "header");
        securitySchemes.add(apiKey);
        return securitySchemes;
    }

    private List<SecurityContext> securityContexts() {
        //设置需要登录认证的路径
        List<SecurityContext> securityContexts = new ArrayList<>();
        // ^(?!auth).*$ 表示所有包含auth的接口不需要使用securitySchemes即不需要带token
        // ^标识开始  ()里是一子表达式  ?!/auth表示匹配不是/auth的位置，匹配上则添加请求头，注意路径已/开头  .表示任意字符  *表示前面的字符匹配多次 $标识结束
        securityContexts.add(getContextByPath());
        return securityContexts;
    }

    private SecurityContext getContextByPath() {
        return SecurityContext.builder()
                .securityReferences(defaultAuth())
                .forPaths(PathSelectors.regex("^(?!/auth).*$"))
                .build();
    }

    private List<SecurityReference> defaultAuth() {
        List<SecurityReference> securityReferences = new ArrayList<>();
        AuthorizationScope authorizationScope = new AuthorizationScope("global", "accessEverything");
        AuthorizationScope[] authorizationScopes = new AuthorizationScope[1];
        authorizationScopes[0] = authorizationScope;
        securityReferences.add(new SecurityReference(tokenHeader, authorizationScopes));
        return securityReferences;
    }


    /**
     * SwaggerUI接口访问
     */
    @Controller
    @ApiIgnore
    @RequestMapping("/swagger")
    public static class SwaggerResourceController implements InitializingBean {

        @Autowired
        private ApiResourceController apiResourceController;

        @Autowired
        private Environment environment;

        @Autowired
        private DocumentationCache documentationCache;

        @Autowired
        private ServiceModelToSwagger2Mapper mapper;

        @Autowired
        private JsonSerializer jsonSerializer;

        private Swagger2Controller swagger2Controller;

        @Override
        public void afterPropertiesSet() {
            swagger2Controller = new Swagger2Controller(environment, documentationCache, mapper, jsonSerializer);
        }

        /**
         * 首页
         *
         * @return
         */
//        @RequestMapping
//        public ModelAndView index() {
//            ModelAndView modelAndView = new ModelAndView("redirect:" + DEFAULT_PATH + "/swagger-ui.html");
//            return modelAndView;
//        }

        @RequestMapping("/swagger-resources/configuration/security")
        @ResponseBody
        public ResponseEntity<SecurityConfiguration> securityConfiguration() {
            return apiResourceController.securityConfiguration();
        }

        @RequestMapping("/swagger-resources/configuration/ui")
        @ResponseBody
        public ResponseEntity<UiConfiguration> uiConfiguration() {
            return apiResourceController.uiConfiguration();
        }

        @RequestMapping("/swagger-resources")
        @ResponseBody
        public ResponseEntity<List<SwaggerResource>> swaggerResources() {
            return apiResourceController.swaggerResources();
        }

        @RequestMapping(value = "/v2/api-docs", method = RequestMethod.GET, produces = {"application/json", "application/hal+json"})
        @ResponseBody
        public ResponseEntity<Json> getDocumentation(
                @RequestParam(value = "group", required = false) String swaggerGroup,
                HttpServletRequest servletRequest) {
            return swagger2Controller.getDocumentation(swaggerGroup, servletRequest);
        }
    }

}

/**
 *  将Pageable转换展示在swagger中
 */
@Configuration
class SwaggerDataConfig {

    @Bean
    public AlternateTypeRuleConvention pageableConvention(final TypeResolver resolver) {
        return new AlternateTypeRuleConvention() {
            @Override
            public int getOrder() {
                return Ordered.HIGHEST_PRECEDENCE;
            }

            @Override
            public List<AlternateTypeRule> rules() {
                return newArrayList(newRule(resolver.resolve(Pageable.class), resolver.resolve(Page.class)));
            }
        };
    }

    @ApiModel
    @Data
    private static class Page {
        @ApiModelProperty("页码 (0..N)")
        private Integer page;

        @ApiModelProperty("每页显示的数目")
        private Integer size;

        @ApiModelProperty("以下列格式排序标准：property[,asc | desc]。 默认排序顺序为升序。 支持多种排序条件：如：id,asc")
        private List<String> sort;
    }
}
